Antenna Positioning Effects and Considerations in RF Shielded Box for Maximum Coupling and Measurement Accuracy

In this paper, the effects and considerations of antenna positioning in RF shielded box that includes an antenna coupler for over-the-air test purposes are explained in detail. Funkwerks state-of-the-art FocX2 handheld radio (Device Under Test, or DUT), which is developed for railway radio communication, is placed inside the box on the antenna coupler. Different locations over the coupler and different placements of the DUT are applied in the band of GSM900 using a radio communication tester, which is connected to the coupler's antenna inside the RF -shielded box, for maximum coupling and better measurement accuracy. Further tests are conducted with a near-field scanner to compare field strength for different configurations of the DUT positioning. The measurement results show the positioning effects on the coupling and receiving level and prove the importance of properly positioned DUT for better measurement accuracy.